Fine mapping and candidate gene analysis of a novel fertility restorer gene for C-type cytoplasmic male sterility in maize (Zea mays L.).

A novel strong fertility restorer gene Rf12 for C-type cytoplasmic male sterility of maize was finely mapped on chromosome 2. Its best candidate gene Zm00001d007531 is predicted to encode a p-type PPR protein. The lack of strong restorer gene of maize CMS-C greatly limits its application in hybrid seed production.

Exploration and utilization of maize male sterility resources.

Male sterility refers to the defective development of male reproductive organs, which led to plants incapable of producing normal and functional pollens. Maize (Zea mays L.) is one of the most important food crops, as well as one of the earliest crops to utilize heterosis in breeding.

Transcriptomic Analysis Reveals Candidate Genes Responding Maize Gray Leaf Spot Caused by .

Gray leaf spot (GLS), caused by the fungal pathogen (), is one of the most destructive soil-borne diseases in maize ( L.), and severely reduces maize production in Southwest China. However, the mechanism of resistance to GLS is not clear and few resistant alleles have been identified.

ZmXTH, a xyloglucan endotransglucosylase/hydrolase gene of maize, conferred aluminum tolerance in Arabidopsis.

Aluminum (Al) toxicity is one of the primary factors limiting crop production in acid soils worldwide. The cell wall is the major target of Al toxicity owing to the presence of many Al binding sites. Previous studies have found that XTH, encoding xyloglucan endohydrolase (XEH) and xyloglucan endotransglucosylase (XET), could participate in cell wall extension and affect the binding ability of the cell wall to Al by impeding the activities of these two enzymes.

The characterization and candidate gene isolation for a novel male-sterile mutant ms40 in maize.

A novel genic male-sterile mutant ms40 was obtained from EMS treated RP125. The key candidate gene ZmbHLH51 located on chromosome 4 was identified by map-based cloning. This study further enriched the male sterile gene resources for both production applications and theoretical studies of abortion mechanisms.

Characterization and Expression Analyses of Callose Synthase Enzyme (Cals) Family Genes in Maize (Zea mays L.).

The callose synthase enzyme genes (Cals) generally plays an important role in resisting to environmental stresses as well as in regulating the microspore development of higher plant. However till now, few researches about ZmCals genes have been reported in maize. In this study, ten ZmCals genes were identified, and they are distributed on four chromosomes in maize.

A Maize Gene Confers Aluminum Tolerance Reactive Oxygen Species Scavenging.

Aluminum (Al) toxicity is the primary limiting factor that affects crop yields in acid soil. However, the genes that contribute to the Al tolerance process in maize are still poorly understood. Previous studies have predicted that ZmAT6 is a novel protein which could be upregulated under Al stress condition.

, a Novel QTL for the Fertility Restoration of Maize CMS-C Identified by QTL-seq.

C-type cytoplasmic male sterility (CMS-C), one of the three major CMS types in maize, has a promising application prospect in hybrid seed production. However, the complex genetic mechanism underlying the fertility restoration of CMS-C remains poorly understood. The maize inbred line A619 is one of the rare strong restorer lines carrying the restorer gene , but different fertility segregation ratios are found in several F populations derived from crosses between isocytoplasmic allonucleus CMS-C lines and A619.

Identification and characterization of the TCA cycle genes in maize.

Background: The tricarboxylic acid (TCA) cycle is crucial for cellular energy metabolism and carbon skeleton supply. However, the detailed functions of the maize TCA cycle genes remain unclear.

Results: In this study, 91 TCA genes were identified in maize by a homology search, and they were distributed on 10 chromosomes and 1 contig.

A novel maize dwarf mutant generated by Ty1-copia LTR-retrotransposon insertion in Brachytic2 after spaceflight.

Retrotransposon insertion in Brachytic2 generated a new incomplete recessive dwarf allele after spaceflight can moderately reduce plant height in heterozygous and potentially improve maize yield. Plant height and ear height are two important agronomic traits in maize breeding. In this study, two dwarf mutants short internode length1 (sil1) and short internode length2 (sil2) were obtained from two of 398 spaceflighted seeds of inbred line 18-599.

The Coix Genome Provides Insights into Panicoideae Evolution and Papery Hull Domestication.

Coix is a grass crop domesticated as early as the Neolithic era. It is still widely cultivated for both highly nutritional food and medicinal use. However, the genetic study and breeding of this crop are hindered by the lack of a sequenced genome.

Comparative transcriptome analysis reveals that tricarboxylic acid cycle-related genes are associated with maize CMS-C fertility restoration.

Background: C-type cytoplasmic male sterility (CMS-C) is one of the three major types of cytoplasmic male sterility (CMS) in maize. Rf4 is a dominant restorer gene for CMS-C and has great value in hybrid maize breeding, but little information concerning its functional mechanism is known.

Results: To reveal the functional mechanism of Rf4, we developed a pair of maize near-isogenic lines (NILs) for the Rf4 locus, which included a NIL_rf4 male-sterile line and a NIL_Rf4 male fertility-restored line.

Molecular and functional characterization of the magnesium transporter gene ZmMGT12 in maize.

Magnesium (Mg) is an essential mineral element for normal plant growth and development, and the CorA/MRS2/MGT-type Mg transporters play a significant role in maintaining Mg homeostasis in plants. In total, 12 maize CorA-like Mg transporters have been identified, but none of them had been functionally characterized. Accordingly, we cloned and functionally characterized ZmMGT12 from the maize CorA-like gene family.

Cloning, molecular evolution and functional characterization of ZmbHLH16, the maize ortholog of OsTIP2 (OsbHLH142).

The transcription factor ZmbHLH16, the maize ortholog of OsTIP2 (OsbHLH142), was isolated in the present study. Tissue expression analysis showed that ZmbHLH16 is preferentially expressed in male reproductive organs. Subcellular location analysis of ZmbHLH16 via rice protoplast indicated that it is located in the nucleus.

The maize CorA/MRS2/MGT-type Mg transporter, ZmMGT10, responses to magnesium deficiency and confers low magnesium tolerance in transgenic Arabidopsis.

ZmMGT10 was specifically expressed in maize roots and induced by a deficiency of magnesium. Overexpression of ZmMGT10 restored growth deficiency of the Salmonella typhimurium MM281 strain and enhanced the tolerance in Arabidopsis to stress induced by low magnesium levels by increasing uptake of Mg via roots. CorA/MRS2/MGT-type Mg transporters play a significant role in maintaining magnesium (Mg) homeostasis in plants.

Comparative transcriptome analysis of isonuclear-alloplasmic lines unmask key transcription factor genes and metabolic pathways involved in sterility of maize CMS-C.

Although C-type cytoplasmic male sterility (CMS-C) is one of the most attractive tools for maize hybrid seed production, the detailed regulation network of the male sterility remains unclear. In order to identify the CMS-C sterility associated genes and/or pathways, the comparison of the transcriptomes between the CMS-C line C48-2 and its isonuclear-alloplasmic maintainer line N48-2 at pollen mother cell stage (PS), an early development stage of microspore, and mononuclear stage (MS), an abortive stage of microspore, were analyzed. 2,069 differentially expressed genes (DEGs) between the two stages were detected and thought to be essential for the spikelet development of N48-2.

Natural antisense transcripts are significantly involved in regulation of drought stress in maize.

Natural antisense transcripts (NATs) are a prominent and complex class of regulatory RNAs. Using strand-specific RNA sequencing, we identified 1769 sense and antisense transcript pairs (NAT pairs) in two maize inbreds with different sensitivity to drought, as well as in two derivative recombination inbred lines (RILs). A significantly higher proportion of NATs relative to non-NATs are specifically expressed under water stress (WS).

A preliminary identification of , a novel restorer gene for CMS-C in maize ( L.).

C-type cytoplasmic male sterility (CMS-C) is widely utilized for hybrid maize seed production. However, genetic mechanisms underlying the fertility restoration are very complicated. At present, there is a divergence on the number of fertility restorer genes in maize inbred line A619 for CMS-C.

Research progress on mechanisms of male sterility in plants based on high-throughput RNA sequencing.

Male sterility is defined as failing to produce functional pollen during stamen development in plants, and it plays a crucial role in plant reproductive research and hybrid seed production in utilization of crop heterosis. High throughput RNA sequencing (RNA-seq) has been used widely in the study of different fields of life science, as it readily detects all the mRNA and non-coding RNA in cells. Recently, RNA-seq has been reported to be applied in different species and kinds of pollen abortion types in plants, which has contributed to the understanding of the molecular mechanism and metabolic networks of male sterility at the transcription level.

[Research progress of the bHLH transcription factors involved in genic male sterility in plants].

Male sterility exists widely in the spermatophytes. It contributes to the study of plant reproductive development and can be used as an effective tool for hybrid seed production in heterosis utilization. Therefore, the study on male sterility is of great value in both theory and application.

Genetic variation for maize root architecture in response to drought stress at the seedling stage.

Although the root system is indispensable for absorption of nutrients and water, it is poorly studied in maize owing to the difficulties of direct measurement of roots. Here, 103 maize lines were used to compare root architectures under well-watered and water-stressed conditions. Significant genetic variation, with medium to high heritability and significant correlations, was observed for root traits.

[Cytological observation and DNA methylation analysis of two new cytoplasmic male sterile lines of maize during microsporogenesis].

Cytoplasmic male sterility (CMS) is a widespread phenomenon in higher plants and has been applied in the commercial production of hybrid seeds. Two CMS lines A1 and A2 of maize were obtained previously by a transgenic experiment. In this study, we conducted cytological observation of developmental microspores with CMS line A1, A2 and their maintainer line (18 red) using paraffin section technology.

Validation of potential reference genes for qPCR in maize across abiotic stresses, hormone treatments, and tissue types.

The reverse transcription quantitative polymerase chain reaction (RT-qPCR) is a powerful and widely used technique for the measurement of gene expression. Reference genes, which serve as endogenous controls ensure that the results are accurate and reproducible, are vital for data normalization. To bolster the literature on reference gene selection in maize, ten candidate reference genes, including eight traditionally used internal control genes and two potential candidate genes from our microarray datasets, were evaluated for expression level in maize across abiotic stresses (cold, heat, salinity, and PEG), phytohormone treatments (abscisic acid, salicylic acid, jasmonic acid, ethylene, and gibberellins), and different tissue types.

Identification of candidate genes for drought tolerance by whole-genome resequencing in maize.

Background: Drought stress is one of the major limiting factors for maize production. With the availability of maize B73 reference genome and whole-genome resequencing of 15 maize inbreds, common variants (CV) and clustering analyses were applied to identify non-synonymous SNPs (nsSNPs) and corresponding candidate genes for drought tolerance.

Results: A total of 524 nsSNPs that were associated with 271 candidate genes involved in plant hormone regulation, carbohydrate and sugar metabolism, signaling molecules regulation, redox reaction and acclimation of photosynthesis to environment were detected by CV and cluster analyses.